Force Testing of Metal IUD in Conventional Medical MRI

CAI Jiancai; ZENG Minguang; GUO Zhaopeng; SHEN Daguang; ZHOU Lixiao; HAN Dingying

Abstract：Objective To establish experimental model to test the interaction of intrauterine device ( IUD) with conventional med-ical magnetic resonance ( MR) , so as to determine whether the patients using IUD could be checked by MRI or not. Methods Mag-netic IUD and non-magnetic copper IUD were placed on the test model respectively. The translational force and torque of various IUD points were tested on 0. 4T, 1. 0T, 1. 5T and 3. 0T MR machine. Results In the 0. 4 T magnetic metal circle center, magnetic metal IUD showed the strongest magnetic force and translational force. The direction of the force pointed to the circle center and had nothing to do with machine scanning;torque was not tested. Superconductive MR outer translational force was obvious on 1. 0 T, 1. 5 T, 3. 0 MR machines with the highest recent lap margin, torque was not tested, magnetic circle maintained magnetic balance, the forces were zero, translational force and torque were zero. Non-magnetic metal copper IUD didn't have translational and torsional forces. The data above had nothing to do with machine scanning. Conclusion The change of the position of magnetic metal IUD happens in the process of entering into the examination room and cavity instead of scanning;while there is no torque in the process of scanning. Non-magnetic copper IUD didn't have translational force and torque tested by conventional medical magnetic resonance (MR), without shifting and bleeding caused by magnetic pulling during testing.